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101.
An exploratory, comparative survey design was used to describe and compare similarities and differences in perception of caring behaviors between hospitalized antepartum and short-stay postpartum patients. Forty-two patients completed the 63-item Caring Behavior Assessment instrument (CBA). The scale, based on Watson's theory of caring, contains seven categories. There were no statistically significant differences in age, education, gravida, or para between the two groups. Significantly more women in the postpartum group were married. There were no statistically significant differences or correlations in the total CBA scores and the demographic variables. No statistically significant differences in total CBA scores were found between antepartum participants and postpartum participants. These findings corroborate the results of "caring" studies in other patient populations, that satisfying basic needs--that is, evidence of technical knowledge and skills--is more important to patients than meeting higher order needs.  相似文献   
102.
Pancreatic cancer is a dismal disease. The 5-year overall survival ranges from 1% to 5%. Surgery is the only curative treatment available for this cancer, but it is indicated only in selected patients with a less than 4 cm tumor. In these patients, survival rate is about 30%. We have considered several aspects: the very difficult early diagnosis, the correct diagnostic flow chart, actual surgical procedures and new trends in biologic and genetic research. It is likely that better results can be achieved by defining an "early pancreatic cancer" and establishing how to detect it. This could be the wrigth one way is to significantly improve the survival of these patients.  相似文献   
103.
The genetic cost of sexual reproduction has been attributed to two causes in mathematical formulations: male function or genome dilution. We develop and analyse a genetic model that shows that both costs occur, depending upon the conditions. The model differs from previous formulations in that the level of output and fertilization success of male gametes produced by hermaphrodites that are asexual in their female function (henceforth "parthenogenetic hermaphrodites") are treated as variables, rather than constants fixed at 0 or 1, as has previously been the case. By expressing the cost of sex in terms of per capita egg loss of sexual individuals and parthenogenetic hermaphrodites, we partition the cost into components due to male function and genome dilution. Which component dominates the cost of sex depends upon the relative male gamete output of the parthenogenetic hermaphrodites. The cost of sex is observed to increase, or remain unchanged in some marginal cases, with increases in (i) frequency of parthenogenetic hermaphrodites, (ii) fertilization success of male gametes produced by parthenogenetic hermaphrodites and (iii) potential eggs lost by diverting resources to male gamete production. In certain situations, parthenogenetic hermaphrodites with an intermediate level of male gamete output have the greatest fitness advantage over sexual individuals. If heritable variation for levels of male gamete output exists among parthenogenetic hermaphrodites, this raises the possibility of the evolution of optimal levels of male gamete production by parthenogenetic hermaphrodites through natural selection, in situations of recurring invasion of asexual populations by propagules from sexual populations, a scenario that is increasingly being appreciated as potentially fairly likely to occur in nature.  相似文献   
104.
Oxidized Escherichia coli thioredoxin (Trx) is a small protein of 108 residues with one disulfide bond (C32-C35 essentially involved in the activity) and no prosthetic moieties, which folds into a structural motif containing a central twisted beta-sheet flanked by helices that is found in many larger proteins. The kinetics of refolding of Trx in vitro have been investigated using a newly developed active site titration assay and continuous or stopped-flow (SF) methods in conjunction with circular dichroism (CD) and fluorescence (Fl) spectroscopy. These studies revealed the presence of early folding intermediates with "molten globule or pre-molten globule" characteristics. Measurements of the ellipticity at 222 nm indicated that about 68% of the total change associated with refolding occurred during the dead time (4 ms) of the stopped-flow instrument, suggesting the formation of substantial secondary structure. The reconstruction of the far-UV CD spectrum of the burst intermediate using combined continuous and stopped-flow methods showed the formation of a defined secondary structure that contains more beta-structure than the native state. Kinetic measurements using SF far-UV CD and Fl over a wide range (0.087-6 M) of GuHCl concentrations at two temperatures (6 and 20 degreesC) demonstrated that the population formed during the 4 ms dead time contained multiple species that are stabilized mainly by hydrophobic interactions and undergo further folding along alternative pathways. One of these species leads directly and rapidly to the native state as demonstrated by active site titration, while the two others fold into a fourth intermediate that is slowly converted to the native protein. Double-jump experiments suggest that the heterogeneity in folding behavior results from proline isomerizations occurring in the unfolded state. Conversely, the accumulation of the burst intermediate does not depend on proline isomerizations.  相似文献   
105.
The purpose of this study was to prospectively evaluate the incidence of noise detection during bradycardia pacing by an FDA approved hybrid nonthoracotomy ICD system. An illustrative case report which prompted this investigation is provided. Backup bradycardia pacing by tiered therapy cardioverter defibrillators has been useful in preventing postshock bradycardia and occasionally for chronic rate support in bradycardic patients. Unexplained "noise" detected by real-time telemetry has been previously described during bradycardia pacing by a device utilizing automatic gain control for sensing. Eighteen patients were prospectively evaluated for noise detection during ventricular pacing by the ICD. Real-time telemetry was analyzed with each patient: (1) supine, (2) supine with deep inspiration/expiration, (3) supine during Valsalva, and (4) during a change in position from supine to sitting. Analysis of pacing threshold and lead impedance was made in each patient. Eleven of 18 patients had noise detected on real-time telemetry during bradycardia pacing. In 10 patients this was noted during deep inspiration/expiration, in 2 during Valsalva maneuver, and in 5 with position change. There was no evidence in any patient of lead malfunction nor any difference in pacing threshold or lead impedance between patients with noise detected versus those without it. Noise detection by an approved hybrid ICD system is common and may be due to the automatic gain control which maximizes sensitivity during bradycardia pacing. This may lead to clinically significant events, with both suppression of bradycardia pacing and triggering of tachycardia therapy in the absence of ventricular tachyarrhythmias in pacemaker-dependent patients.  相似文献   
106.
The success of radiotherapy in eradicating tumours depends on the total radiation dose, but what limits this dose is the tolerance of the normal tissues within the treatment volume. Studies involving fibroblast survival have demonstrated the theoretical feasibility of a predictive assay of radiation sensitivity, but such an assay is still far from clinical application. Using pulsed-field gel electrophoresis (PFGE), we have quantified the initial "apparent" number of DNA double-strand breaks (dsb) induced by the radiation as an alternative measure of sensitivity in 2 different normal cell types from the same patients, epidermal skin cells and lymphocytes. We found significant inter-individual variation in the measured dsb (1-5 dsb/Gy/DNA unit). We also found a linear correlation between molecular damage in lymphocytes and skin samples from the same patient (slope = 0.83; r = 0.694; p = 0.0001). These results suggest that the initial number of dsb could be used as an indicator of the in vivo response to radiation.  相似文献   
107.
Cerebellar Purkinje cells (PC) display a highly distinctive form of polarity. We have cultured murine PCs from dissociated E16 cerebellar anlagen for 1 week to investigate the early stages of neuronal compartmentalization and synaptic interactions, features which are important for the establishment of neuronal polarity. To unequivocally identify the PCs we utilized light and electron microscopic immunocytochemistry with an anti-serum to the cell class-specific marker L7/pcp2 gene product. The PCs typically show a single, long axon, numerous short appendages classified as filopodia and protospines, and a small number of protodendrites. The nucleus is positioned asymmetrically in both the horizontal and vertical axes of the soma. The Golgi apparatus, coated and uncoated vesicles, and mitochondria are prominent ultrastructural features, while the endoplasmic reticulum is highly fragmented. The cell body receives rudimentary synapses on its smooth surfaces and appendages and no consistent morphological differences were detected between these elementary contacts. The axon is clearly identifiable; it emanates from either the cell body or a protodendrite, bifurcates at predominantly right angles, forms beaded collaterals, and terminates with relatively large growth cones. The varicosities of the PC axon contain pleomorphic synaptic vesicles and form rudimentary synapses primarily with the dendritic shafts of immunonegative neurons. The protodendrites are short, quickly tapering and sparsely branched; they emit numerous filopodia and immature spines and terminate with small growth cones. Rudimentary synapses are received on the proximal dendritic shafts and filopodia, and more mature synapses occur frequently on protospines. With few exceptions, PCs lie atop an astrocytic bed layer and glial processes are apposed to the various aspects of the PC body left free by the afferent axons. By contrast, PC processes are largely free of glial sheaths. We conclude that the "stellate stage" of PC development in situ is replicated rather faithfully in culture and that PCs have established polarity and have begun to form intercellular contacts by 1 week in vitro. Moreover, the PCs are already morphologically distinct from other cell types in the 1 week cultures, although they have yet to develop the differentiated features that distinguish mature PCs.  相似文献   
108.
We report polarization-dependent angle-resolved photoemission studies of single crystalline Ba2Cu3O4Cl2. This antiferromagnet adopts a layered body-centered tetragonal structure related to that of the cuprates, but with anextra copper site resulting in a plane with Cu3O4 stoichiometry. For the -M direction of the Brillouin zone we observe a dispersive feature with a bandwidth of 400 ±80 meV, which approaches to within 0.9 eV of the Fermi level at (/2,/2). The magnitude of the observed dispersion and its polarization dependence are consistent with its origin as a purely antibonding combination of O2px,y and atomic orbitals from the cuprate-like CuO2 sub-system, i.e. Zhang-Rice singlets.  相似文献   
109.
BACKGROUND: Clinical manifestations and course of sickle-cell anemia are variable. Knowledge about the factors, possibly geographic, that influence prognosis are still scanty. POPULATION AND METHODS: Data of hospitalization and management of children with sickle-cell disease were studied during two years (1992-1993) in the Pediatric Unit of Libreville Hospital. They concerned 205 admissions of 171 children and 131 outpatients. RESULTS: The main causes of hospitalization were: acute anemia (36 cases before the age of 5 years); painful crisis whose frequency increased with age (23% before 5 years, 35% between 5 and 10, 42% after 10 years); infections, essentially pulmonary occurring early, and bone infections at any age. Eight children died (because a complication of their disease). Among the 131 outpatients, half were detected because pyrexia, anemia and/or more often "hand-foot syndrome". More than 60% had hepatomegaly, one third still had splenomegaly after five years of age and more than one third was icteric. More than half children older than ten years had growth disorders. Mean hemoglobin level was 7 g/dL. 21 of the 83 tested children for HBsAg were positive and only one out of 79 was positive for HIV. CONCLUSIONS: Clinical manifestations and course of sickle-cell anemia in our patients are similar to those reported in Congolese children. Genetic and environmental factors may be responsible for differences with children from other, in particular French, cohorts.  相似文献   
110.
设计并实现了一种基于Lotus Notes的分布式信息邮政商业信函系统,并研究了系统实现过程中的两个关键技术。  相似文献   
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